A conventional stroller comprises two front legs, two rear legs each pivotally connected with one of the two corresponding front legs, two push handles each secured to one of the two corresponding front legs, a substantially U-shaped handlebar connected between the two push handles, a supporting frame pivotally mounted between the front legs and the rear legs, a flexible seat mounted on the supporting frame, and a folding device for folding the front legs and the rear legs. The folding device essentially comprises a pivot hook in conjunction with locking bosses. By such an arrangement, however, the stroller cannot be folded easily by means of the engagement between the hook and the locking boss, thereby causing inconvenience when being in use. In addition, the exposed hook tends to scrape the human body, thereby easily injuring the user. Further, a shoulder strap fitted between the handlebar and the push handle can be suspended on one of the user's shoulders such that the stroller can be carried on one of the user's shoulders only when it is folded, thereby easily causing force imbalance to the user's body. The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional stroller.